An image forming apparatus or system of a specific type known in the art has a structure configured to allow a developer container (e.g., embodied in a development cartridge) in which developer is storable, to be installed in or removed from the main body. To be more specific, for example, a development cartridge may include a developer container having a lid member and a container body openably closed with the lid member, and an agitating member configured to agitate developer in the developer container. In some configurations, optionally, the capacity of the developer container can be changed by changing the lid member into another lid member having a different shape.
When the developer storage capacity of the development cartridge is changed by replacing one developer container with another developer container which has a differently shaped lid member, changes would also be effected in various properties such as the position of the center of rotation, the radius of rotation, the rotation speed, and the length and thickness of the agitating member. This would result in the change of the performance of the agitating member in agitating and conveying the developer.
There is a need of maintaining the performance of the agitating member in agitating and conveying developer, while the developer container can be adapted to have an intended capacity corresponding to a desired amount of developer to be stored in the developer container.